Wall Street Journal article 7/12: Spicy End to Muscle Cramps. sorry i cannot print this article due to its length to will paraphrase a summary here: Nobel winner Rod MacKinnon had muscle cramps while kayaking and did not believe it was from dehydration, fatigue or lack of electrolytes. His study showed that primary origin of cramp is the nerve, not muscle.
Seeking to avoid cramps by regulating excessive firing of motor neurons, he and colleagues constructed the first atomic model of the protein models that make electrical signals in living organisms.
MacKinnon and Bruce Bean believed they could modify the nervous system in cluding the neurons controlling muscle by applying a strong sensory input and stimulating receptors in the mouth and esphagus - tasting pungent overloads of foods which would provide a numbing effect.
MacKinnon, "The strong sensory nput causes inhibition of the motor output."
After years of trial and error on himself, he concluded that it is harded to induce cramps after indulging in spicy concoctions. Studies followed with similar results.
The irony is that for years athletes have used pungent liquids like pickle juice, beets or sour cherries to avoid cramp. They were on to something, just not the right something.
MacKinnon has developed a company (surprise!) which markets Hotshot, a mix of ginger, cinnamon and capsicum (red pepper). It's not your usual cool, citrus-flavored drink....it packs a jolt.
The point is to shock the system, not replenish it.
My words: Maybe this is why people with swallow problems do better when swallowing iced drinks than not.
What implications could this have with regard to regulating the firing of neurons in PD? i recall reading about a child in Canada with diabetes who was given capsicum and it worked. also, there is a bit on google about the use of it that way.